The present invention relates to a metal-clad, compressed gas-blast circuit-breaker having a gas-filled housing and an interrupter unit, which is supported in the housing by a hollow post insulator and whose movable switching contact is connected to a shifting linkage penetrating the post insulator. The shifting linkage comprises at least one insulating drive rod, whereby the post insulator at its one end area bears the interrupter unit and is secured at its other end area to an outer support of the housing.
Such a metal-clad, compressed gas-blast circuit-breaker is known from GB No. 2,089,571A. In the case of this known circuit-breaker, the shifting linkage consists of a combination of insulating and metallic drive rods between the interrupter unit and the location where a driving movement supplied by an external drive unit is introduced into the housing of the circuit-breaker. Thereby, during the breaking movement or rather in the switch-off position, the lower end of the metallic drive rod projects into the interior of the hollow post insulator, which is thereby dielectrically stressed. In addition, in the case of the post insulator, the metallic mounting reinforcements are fused in the walls and thus form a part of the post insulator.